Severe Influenza in Children: Beyond Respiratory Illness
Recent research highlights the notable burden of influenza in children, extending beyond typical respiratory symptoms and leading too serious, sometimes fatal, complications.A extensive study analyzing data from a large cohort of hospitalized children demonstrated a substantial proportion develop non-respiratory manifestations of the flu, with concerning rates of morbidity and mortality.
The study revealed that children hospitalized with influenza experienced a median hospital stay of 3.9 days. A notable 31% required mechanical ventilation, and the in-hospital mortality rate reached 5.2%. Cardiovascular complications were notably deadly, accounting for nearly 19.7% of deaths. These findings are consistent with existing data indicating that systemic and neurological complications,such as encephalopathy and acute necrotizing encephalopathy,are frequently observed during pediatric influenza seasons and can result in severe neurological damage and death.
Analysis across multiple influenza seasons confirms that multi-system involvement is common in pediatric cases. The Centers for Disease Control and Prevention (CDC) reports that neurological complications, including influenza-associated encephalopathy (IAE) and acute necrotizing encephalopathy (ANE), are major contributors to increased pediatric mortality in recent years, emphasizing the potential for influenza to cause severe illness even when it doesn’t primarily affect the respiratory system.
These findings have vital implications for healthcare professionals, particularly pharmacists. Worldwide influenza immunization, recommended for all children aged 6 months and older, remains the primary preventative measure. Recent declines in pediatric vaccination coverage are a concern, especially considering the high incidence of non-respiratory complications. Advocating for vaccination, particularly for children with underlying medical conditions, is crucial.
Furthermore, the study showed a concerning trend of reduced antiviral use in children presenting with non-respiratory symptoms. Early empiric antiviral therapy should be considered for all hospitalized children suspected of having influenza, irrespective of their initial symptoms. Prior research, including studies from past pandemics, supports initiating antiviral treatment early to prevent severe complications, especially in high-risk children.
this extensive multi-season study underscores the significant risk of non-respiratory complications in hospitalized children with influenza, and the associated morbidity and mortality. Children presenting with non-respiratory symptoms tend to be older, have pre-existing medical conditions, are more likely infected with influenza B, and are less frequently treated with antivirals. Improved recognition of these diverse manifestations, coupled with maximizing vaccination rates and timely antiviral therapy, are vital strategies to improve outcomes for pediatric patients affected by influenza.
REFERENCES
- Kamidani S, Witt LS, Patterson A, et al. Respiratory and Nonrespiratory Complications in Children Hospitalized with Influenza in the Post-2009 H1N1 Pandemic Era. presented at: IDWeek 2025; October 21, 2025; atlanta, GA. Accessed november 3, 2025, via IDWeek’s online conference platform.
- Libster R, Bugna J, Coviello S, et al. Pediatric hospitalizations associated with 2009 pandemic influenza A (H1N1) in Argentina. The New England Journal of Medicine. 2010;362(1):45-55.doi:10.1056/NEJMoa0907673
- Reinhart K, Huang S, Kniss K, Reed C, Budd A. Influenza-Associated pediatric Deaths – United States, 2024-25 influenza Season. MMWR Morbidity and Mortality Weekly Report. 2025;74(36):565-569. doi:10.15585/mmwr.mm7436a2
